The invention relates to military observation posts (generally, but not necessarily, constituted by a turret) equipped with two superimposed sighting devices, namely a rough external sighting device and an internal precision sighting device having a reduced field of view compared to the external sighting device, said internal sighting device being generally utilized by the observer in the final phase of pursuit of an objective which has been initially sighted by the external sighting device.
It is noted that the expression "military equipment" is used hereafter in a very general sense and it relates to equipment of fixed type, such as, for example, observation blockhouses and fortresses, as well as mobile equipment such as vehicles (ground, naval or aerial) equipped with an observation post generally in the form of a turret or a bubble (a turret of small diameter).
Furthermore, the military equipment according to the invention can be a simple observation post or, in the more general case, it can include at least one gun (automatic cannon or machine gun) operated by the observer.
In this domain of relatively wide utilization of military equipment (fixed or mobile, with or without a gun) the invention is particularly but not exclusively directed to armored vehicles with a gun turret equipped with an external rough sighting device and an internal precision sighting device, the gun carried by the turret (for example, mounted exteriorly on its roof) being then controlled in angle of elevation from the interior of the turret. Military ground vehicles of this type can be combat vehicles such as tanks, armored cars etc, reconnaissance vehicles or personnel carriers (wheeled or tracked).
For military equipment of this type, it is important that the observer, once that he has sighted an objective in the external rough viewing device can rapidly again find this objective in the internal precision sighting device and perfect his observation mission or even a firing mission with the aid of said internal sighting device.
To this effect, it has already been proposed to correlate the aiming and elevation movements of the external and internal sighting devices, particularly in the case of a turret of an armored car carrying a gun and the two superimposed sighting devices (external and internal viewers), wherein the sighting devices are coupled to follow the aiming and elevation movements of the gun such that the optical axes of the two sighting devices and the axis of the gun remain constantly parallel.
However, this arrangement of correlation of the aiming of the internal and external sighting devices does not afford, in military equipment of the type described, entirely satisfactory results from the point of view of convenience, rapidity and precision for the operator in going from the work position at the external viewer to the work position at the internal viewer.
In practice, the observer generally utilizes the external viewer while standing up with his head disposed in an observation opening and therefore when he is to utilize the internal viewer, he must sit down within the observation post in an attitude entirely different from the standing position which he previously assumed. Moreover, rapid change from the standing position to the seated position is generally prevented by the small size and complexity of the observation post and by general equipment carried by the observer.
Furthermore, during the greatest portion of the mission (travel advance, reconnaissance, sighting of targets, etc.) the observer is standing which is uncomfortable and tiring, particularly in the case of a ground vehicle which travels on rough terrain.
All of these disadvantages mentioned above prevent the observer from accomplishing his mission under the best conditions and with maximum efficiency.